"Canadian theatre has lost one of its greatest talents and a guiding light in its development," the festival's artistic director, Antoni Cimolino, said in a press release on Sunday, according to CTV.

"Douglas Rain was that rare artist: an actor deeply admired by other actors."

Rain was born in Winnipeg, Manitoba, in 1928, studied at the Old Vic in London, and performed at theatres and festival across Canada.

HAL 9000 computer from 2001: A Space Odyssey.

He received a Tony nomination in 1972 for his role in Robert Bolt's production of Vivat! Vivat! Regina!

All of Rain's voiceover work for HAL was done in post-production. Other actors were considered for the role, including Martin Balsam, who was eventually dismissed as too American, and Nigel Davenport, who was too English.

Kubrick decided to deal with the problem in post-production. As a result, he gave his assistant director, Derek Cracknell, the job for the duration of shooting.

Cracknell had a strong Michael Caine-esque accent, which provided for some interesting stories after the film hit cult status.

Baby Driver director Edgar Wright remembered Rain on Twitter.

"One of the best performances in film, with just his voice," he wrote.